Greencore is to temporarily cease production at its Northampton facility in the UK from the end of today as a result of the ongoing Covid-19 outbreak in the Northampton area and at the site.
Greencore is the largest maker of pre-packed sandwiches in the UK and supplies most of the big retailers including Tesco, Marks & Spencer, Waitrose and Sainsbury's.
The Northampton plant services just Marks and Spencer and employs 2,000 people.
As of last week, 300 had tested positive for Covid-19 and the company was not able to say today whether that figure had risen since.
The convenience food group said the decision to cease production will allow all remaining staff at the site to self-isolate as a precautionary measure.
It also said the decision had been taken as part of the region's ongoing efforts to reduce the spread of the virus and keep its workers safe.
Greencore said it has been in constant contact with PHE East Midlands, Northamptonshire County Council, Northampton Borough Council and other government bodies, who have been hugely understanding and supportive of its response to the coronavirus outbreak.
"We will continue to work closely with them in order to bring the site back safely into production as soon as possible, as colleagues who are self-isolating begin to return," the company added.
The company said it has moved a proportion of production from the Northampton facility to other sites within the Greencore network, and are working with the affected customer to help mitigate any shortfall.
The Northampton area today became an "area of intervention" as a result of the rising number of cases there.